1. Field of the Invention
The present invention relates to swimming pool and spa floor drain assemblies, and more particularly to pool floor drain assemblies having an outlet coupled to a water return line which transfers water from a pool or spa to a pump.
2. Description of the Prior Art
U.S. Pat. No. 3,940,807 (Baker) discloses a safety suction outlet for pools and utilizes radially extending tubes to inhibit drain flow blockage.
U.S. Pat. No. 4,115,878 (Johnson) discloses a spa safety drain having a conventional grating or cover protecting a chamber which includes a secondary bypass feature.
U.S. Pat. No. 4,658,449 (Martin) discloses a protective adaptor for a pool drain designed to be placed above a pool floor drain grating to define a raised screening surface for screening any water flowing into the drain to prevent whirl-pooling effect in the drain.
U.S. Pat. No. 5,268,096 (Robol) discloses a typical cavity style prior art pool floor drain having a perforated grating or cover, an underlying cylindrical chamber and a horizontally oriented suction line.
U.S. Pat. No. 5,341,523 (Barnes) discloses an anti-vortex drain which avoids the requirement for a grating by providing a circular cover in combination with a spaced apart circular lip placed above a cylindrical sump chamber having a horizontal suction line.
U.S. Pat. No. 5,734,999 (Nicholas) discloses a safety device for swimming pools which includes a floor drain grate having two or more water inlet systems one of which is spaced widely apart from the primary drain to reduce the probability of that a bather will block the floor drain assembly.
U.S. Pat. No. 5,753,112 (Barnes) discloses a main drain leaf removal system for swimming pools which includes a cylindrical inner chamber with an inlet port elevated above the swimming pool floor and a larger diameter concentrically disposed cylindrical outer chamber having an inlet system level with the pool floor. Separate suction pipes transfer water from the inner and outer chambers. The outer chamber is designed to serve as a leaf removal chamber.
U.S. Pat. No. 5,759,414 (Wilkes) discloses a swimming pool main drain assembly having a domed top including both water inlets as well as a centrally located water outlet.
U.S. Pat. No. 6,038,712 (Chalberg) discloses a safety suction assembly for use in whirlpool baths which includes a safety relief vent located in the center of the drain cover which is activated when the drain is blocked.
U.S. Pat. No. 6,088,842 (Barnett) discloses a drain assembly for preventing hair entanglement in a pool or hot tub and illustrates a slotted grate as well as other grate configurations all having tapered lower grate surfaces.
U.S. Pat. No. 6,230,337 (Barnett) discloses an anti-vacuum drain cover having an elevated grating as well as spoke-like water inlets located at the pool floor level, the openings of which are spaced apart from the central point of the pool floor drain.